Answer:
7.941
Explanation:
You can look at a picture of the periodic table.To calculate the atomic mass of a single atom of an element, add up the mass of protons and neutrons. Example: Find the atomic mass of an isotope of carbon that has 7 neutrons. You can see from the periodic table that carbon has an atomic number of 6, which is its number of protons.
Hope I helped
Answer:
Explanation:
The actual boiling point is probably between 34C and 40C.
Radioactive material undergoes 1st order decay kinetics.
For 1st order decay, half life = 0.693/k
where k = rate constant
k = 0.693/half life = 0.693/8.02 = 0.0864 day-1
Now, for 1st order reaction,
k =
Given: t = 6.01d, initial conc. = 5mg
∴0.0864 =
∴ final conc. = 2.975 mg
True.
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Answer: C) Elements and pure compounds are homogeneous materials because they have a uniform composition throughout.
Explanation: Element is a pure substance which is composed of atoms of similar elements. Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Elements are compounds form homogeneous materials as they have uniform composition throughout and the components are evenly distributed throughout the material.
Mixtures are heterogeneous materials as they do not have uniform composition and the components are not evenly distributed throughout the material.
